*{
    margin: 0;
    padding: 0;
}
#box{
    width: 400px;
    height: 500px;
    background: pink;
    
}
#box ul::after{
    content: "";
    display: block;
    clear: both;
    height: 0;
}
#box li{
width: 100px;
height: 60px;
background: skyblue;
float: left;
list-style: none;
}
#box p{
    width: 400px;
    height: 440px;
    background: thistle;
    display: none;
}
#box .active{
    background: tomato;
    font-weight: bold;
}
#box .play{
    display: block;
}